The invention relates to a rotary mechanism for converting a reciprocal linear motion of an actuator, e.g. constituted by a piston-cylinder unit controlled by a pressurized fluid, into an oscillating rotary motion of an output shaft.
In known rotary mechanisms of this kind, e.g. operating with rack and gear means, a maximum torque is obtained between the end positions of the rotary motion, or a constant torque is developed during the entire stroke. However, such a characteristic is often disadvantegeous. In case, e.g., the rotary mechanism is to be used for operating a valve between open and closed positions, a maximum torque is needed especially in these end positions.